The present invention relates generally to devices with printed sheet material conveyors, for example rotary gatherers, and to conveyors used to carry printed sheet materials, and to pins used to push printed sheet materials.
U.S. Pat. No. 3,825,247 describes a rotary gatherer having a plurality of gripper drums delivering printed sheet materials such as signatures to a conveyor. Pins which extend perpendicularly from the conveyor chain define pockets for the gathered signatures in a conveying direction. U.S. Pat. No. 3,825,247 is hereby incorporated by reference herein.
In addition to rigid pins extending from the conveyor chain, FIG. 1 shows a prior art device in which the pin 4 is mounted on a single pivot 6 attached to a base fixed to the chain 8.
A pin that consists of a round plastic rod or tub and fixed via a base to the chain is also known.
Drop down guards may be required to limit access to the raceway defined by the conveyor chain. Raising and lowering the guards can significantly increase downtime of a rotary gatherer. A main reason for the drop down guards is to protect against hazards created as the pins pass underneath the drums.